What is screening?

Screening is a way of identifying apparently healthy people who may have an increased risk of a particular condition. The NHS offers a range of screening tests to different sections of the population.

The aim is to offer screening to the people who are most likely to benefit from it. For example, some screening tests are only offered to newborn babies, while others such as breast screening and abdominal aortic aneurysm screening are only offered to older people.

Screening results

If you get a normal result (a screen negative result) after a screening test, this means you are at low risk of having the condition you were screened for. This does not mean that you will never develop the condition in the future, just that you are low risk at the moment.

If you have a higher-risk result (a screen positive result), it means you may have the condition that you've been tested for. At this point, you will be offered further tests (called diagnostic tests) to confirm if you have the condition. You can then be offered treatment, advice and support.

Finding out about a problem early can mean that treatment is more effective. However, screening tests are not perfect and they can lead to difficult decisions about having further tests or treatment.

Read on to find out about the benefits, risks and limitations of screening.

What types of screening are offered by the NHS in England?

An independent expert group called the UK National Screening Committee (UK NSC) advises the NHS, in all four UK countries, on which screening programmes to offer. The NHS screening programmes currently offered in England are listed below. For more detailed information on each type of screening, follow the links.

Screening for newborn babies

Diabetic eye screening

From the age of 12, all people with diabetes are offered an annual diabetic eye test to check for early signs of diabetic retinopathy.

Cervical screening

Cervical screening is offered to women aged 25 to 64 to check the health of cells in the cervix. It is offered every three years for those aged 26 to 49, and every five years from the ages of 50 to 64.

Breast screening

Breast screening is offered to women aged 50 to 70 to detect early signs of breast cancer. Women over 70 can self-refer.

Bowel cancer screening

Bowel scope screening uses a thin, flexible tube with a tiny camera on the end to look at the large bowel. It is offered to men and women at the age of 55 in some parts of England.

Abdominal aortic aneurysm (AAA) screening

AAA screening is offered to men in their 65th year to detect abdominal aortic aneurysms (a dangerous swelling in the aorta). Men over 65 can self-refer.

Benefits, risks and limitations of screening

Making an informed choice

Before having any screening test, it's worth finding out about the test itself and what would happen next if you found out you have a higher risk of a particular condition.

Deciding whether or not to have a screening test is a personal choice and one which only you can make. When you are invited for screening, you will receive an information leaflet about the screening test. You can discuss any aspect of the screening test with your health professional and decide whether or not it's right for you.

Different types of screening have different benefits and risks. Some of these are listed below.

The benefits of having a screening test include:

Screening can detect a problem early, before you have any symptoms.

Finding out about a problem early can mean that treatment is more effective.

Finding out you have a health problem or an increased risk of a health problem can help people make better informed decisions about their health.

Screening can reduce the risk of developing a condition or its complications.

Screening can save lives.

The risks and limitations of screening include:

Screening tests are not 100% accurate. You could be told you have a problem when you don't – this is called a "false positive" and may lead to some people having unnecessary further tests or treatment as a result of screening. A screening test could also miss a problem – this is called a "false negative" and could lead to people ignoring symptoms in the future.

Some screening tests can lead to difficult decisions. For example, if a pregnancy screening test tells you your baby has a higher risk of a particular condition, you may then be faced with a decision about having further diagnostic tests that involve a risk to your pregnancy. If the diagnostic test is positive, you may then need to decide whether to continue with your pregnancy.

Finding out you may have a health problem can cause considerable anxiety.

Even if your screening test result is normal or negative (i.e. you are not at high risk), you could still go on to develop the condition.

How does the NHS decide which types of screening to offer?

An expert group called the UK NSC advises the NHS on which screening programmes to offer.

When considering who to screen and which conditions to screen for, the benefits of offering a screening programme are weighed up against the harms. The UK NSC only recommends screening when it believes the benefits to the group offered screening outweigh the harms.

The UK NSC regularly reviews its recommendations on screening for different conditions as new research becomes available. This is usually done every three years.

Private screening

All screening tests provided by the NHS are free. Private companies offer a range of screening tests that you have to pay for. Some of the tests on offer are not recommended by the UK NSC because it is not clear that the benefits outweigh the harms.

Confidentiality and use of data

By law, everyone working in, or on behalf of, the NHS must respect your privacy and keep all information about you safe. The NHS Constitution sets out how the NHS should handle your records to protect your privacy. There are also laws in place to ensure that confidentiality is maintained.

Screening records are only shared with staff who need to see them, such as technicians carrying out screening, your GP and any clinicians involved in follow-up tests and treatment. Anonymised data is sometimes used for research purposes to improve screening outcomes and the quality of services provided by the NHS.

Questions about screening results

For breast screening, cervical screening or bowel cancer screening, contact your GP, who should receive a copy of your results. You can also contact your local breast screening unit, or call the bowel cancer screening helpline on 0800 707 6060.

Questions about symptoms

Speak to your GP if you have any concerns about your health or need to ask about a family history of cancer.